Breaking down heat alerts, discussing heat illnesses

DULUTH, MN– As summer gets into full swing, temperatures are forecasted to get hot, and they can pose a threat to life, and sometimes even property.

While the Northland doesn’t see a prolonged stretch of extreme temperatures all that often, it can happen, and it’s important to know to the signs and symptoms of heat exhaustion and heat stroke, plus the different heat alerts that the National Weather Service (NWS) can issue.

There are three different types of heat alerts the NWS can issue if the forecast is predicting extremely high temperatures:

  1. EXCESSIVE HEAT WATCH: This means that conditions are favorable for a stretch of excessive heat within the next 24 to 72 hours. Watches are issued if the probability of a heat wave has increased, but the timing and length of heat wave is uncertain.
  2. HEAT ADVISORY: This is issued within 12 hours before the dangerous heat conditions are set to begin. Those within the advisory should take precautions to avoid any heat illnesses. The criteria for the issuance of a heat advisory includes the following:
    • The maximum heat index temperature is expected to be at least 100 degrees or higher for a minimum of two days and the night-time air temperature will stay at or above 75 degrees.
  3. EXCESSIVE HEAT WARNING: This is also issued within 12 hours before the dangerous heat conditions are set to begin. Precautions need to be taken seriously or you could become seriously ill or even die. The criteria for the issuance of an excessive heat warning includes the following:
    • The maximum heat index temperature is expected to be at least 105 degrees or higher for a minimum of two days and the night-time air temperature will stay at or above 75 degrees.

It’s important to note that the heat advisory and excessive heat warning criteria varies across the country, especially in areas that don’t see the dangerous heat as often as other parts.

The NWS may also issue an excessive heat outlook as well, if the potential for an excessive heat event is possible within the next three to seven days, and this gives those the time to prepare for the event.

Officials at the Duluth NWS said June 29 through July 1, 2018 was when the last heat advisory was issued, while the last excessive heat warning was issued from July 16 through July 20, 2011.

HEAT INDEX: We hear all the time in the summer of the heat index, but what exactly is it? According to the NWS, the heat index is what it actually feels like to the human body when you combine the relative humidity and the air temperature.

When your body starts to get too hot, you begin to sweat in order to cool yourself off, and since evaporation is a cooling process, if the sweat is not able to evaporate, the body can’t regulate its temperature. When the temperature can’t be regulated, this causes an increase in your body temperature.

Shown below is the heat index chart, courtesy of the NWS


When temperatures get really hot, it can cause health impacts, and can even be deadly in some cases. The most common types of heat illnesses are heat exhaustion and heat stroke.

HEAT EXHAUSTION: Signs of heat exhaustion include:

  • Sweating
  • Weakness
  • Fast and weak pulse
  • Dizziness
  • Fainting
  • Nausea or vomiting

If someone experiences heat exhaustion:

  • Move them to a cooler environment
  • Apply cool, wet cloths to as much of the body as possible
  • Offer sips of water
  • Move to a room with fans or air conditioning
  • If they vomit more than once, seek medical attention

HEAT STROKE: This is more serious, and these symptoms can include:

  • One being in an altered mental state
  • Confusion
  • Nausea
  • Dizziness
  • Headache
  • Skin that is hot, red, dry or moist
  • Body temperature of at least 103 degrees
  • A rapid and strong pulse
  • Person faints or loses consciousness

If someone experiences a heat stroke

  • Call 911 or get the person to the hospital immediately
  • Move the person to a cooler, air-conditioned environment
  • DO NOT give the person fluids
  • Reduce the body temperature with cool cloths or a bath

For more information on the heat-related illnesses, click here.

As we head into the weekend into early next week, the Northland will experience some of the warmest, if not the warmest, temperatures of the season as a big ridge in the jet stream develops and then will flatten out into next week, but the warm temperatures will continue as well.

Here are some tips to keep in mind if you plan to be outside for an extended period of time to prevent heat illnesses:

  • Drink plenty of water
  • Take frequent breaks in the shade or in an air-conditioned environment
  • Check on the pets, children and elderly, as they can be the most susceptible to the heat
  • Wear light weight and loose fitting clothing
  • Limit your outdoor activity during the hottest part of the day, which is roughly from 10 AM to 6 PM. If you want to do any outdoor activities, do them in the early morning hours, or in the mid-evening hours towards sunset.

Click here for the latest forecast, including to see if any heat alerts are issued for your area.  To receive the latest alerts for your area, download the KBJR 6 weather app.

Austin Haskins

Austin Haskins

Meteorologist/Web Producer

KBJR 6 Weather Authority

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